Historically barriers to development in the U.S., such as the dry deserts of some of the country's western states, have been solved by

In a graph for a firm in pure competition with the quantity of output measured on the horizontal axis, the total revenue curve is:

A. Downward-sloping B. Horizontal C. Vertical D. Upward-sloping

Which of the following would decrease the total output of goods and services?

A. Mandatory controls on production B. Increases the hours of work C. Increases in labor input growth D. Increases in capital stock